It could be argued that the fact that tribunals still considered the Barcelona Traction rule to be a true statement of customary international law was the driving force behind the desire of States to enter into bilateral or multilateral investment treaties.
Podría alegarse que el hecho de que los tribunales sigan considerando que la regla de la Barcelona Traction constituye una fiel interpretación del derecho internacional consuetudinario explica la voluntad de los Estados de concertar acuerdos bilaterales o multilaterales sobre inversiones.